Our cat litter boxes have an automatic air freshener dispenser above them to keep their toilet areas smelling okay. Combined with our use of baking soda, regular air fresheners and scented candles, this makes our home smell all right even with cat pee and poo from three cats. The dispenser costs about $12.95 with 2 batteries and one can of fragrance, First Choice brand available in Giant, Cold Storage or Shop and Save.
I use two fragrances - one is lavender scented, costs about $4.95 per can, First Choice brand. The other is cotton scented, a hypoallergenic fragrance from Ambi-Pur which costs about $7.40 a can. I stay away from citrus fragrances because cats are allergic or at least refrain from going near citrus smells.